Author
Masayoshi Tonouchi
Other affiliations: Renesas Electronics, Hamamatsu Photonics, Ibaraki University ...read more
Bio: Masayoshi Tonouchi is an academic researcher from Osaka University. The author has contributed to research in topics: Terahertz radiation & Laser. The author has an hindex of 38, co-authored 568 publications receiving 11335 citations. Previous affiliations of Masayoshi Tonouchi include Renesas Electronics & Hamamatsu Photonics.
Papers published on a yearly basis
Papers
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TL;DR: An overview of the status of the terahertz technology, its uses and its future prospects are presented in this article, with a focus on the use of the waveband in a wide range of applications.
Abstract: Research into terahertz technology is now receiving increasing attention around the world, and devices exploiting this waveband are set to become increasingly important in a very diverse range of applications. Here, an overview of the status of the technology, its uses and its future prospects are presented.
5,512 citations
TL;DR: A film of highly aligned single-walled carbon nanotubes that acts as an excellent terahertz linear polarizer that demonstrates nearly perfect alignment as well as intrinsically anisotropic terAhertz response of single-Walled carbon Nanotubes in the film.
Abstract: We describe a film of highly aligned single-walled carbon nanotubes that acts as an excellent terahertz linear polarizer. There is virtually no attenuation (strong absorption) when the terahertz polarization is perpendicular (parallel) to the nanotube axis. From the data, the reduced linear dichrosim was calculated to be 3, corresponding to a nematic order parameter of 1, which demonstrates nearly perfect alignment as well as intrinsically anisotropic terahertz response of single-walled carbon nanotubes in the film.
253 citations
TL;DR: These results not only provide fundamental insight into the electromagnetic response of Dirac fermions in graphene but also demonstrate the key functionalities of large-area graphene devices that are desired for components in terahertz and infrared optoelectronics.
Abstract: We have fabricated a centimeter-size single-layer graphene device with a gate electrode, which can modulate the transmission of terahertz and infrared waves. Using time-domain terahertz spectroscopy and Fourier-transform infrared spectroscopy in a wide frequency range (10–10 000 cm–1), we measured the dynamic conductivity change induced by electrical gating and thermal annealing. Both methods were able to effectively tune the Fermi energy, EF, which in turn modified the Drude-like intraband absorption in the terahertz as well as the “2EF onset” for interband absorption in the mid-infrared. These results not only provide fundamental insight into the electromagnetic response of Dirac fermions in graphene but also demonstrate the key functionalities of large-area graphene devices that are desired for components in terahertz and infrared optoelectronics.
245 citations
TL;DR: Potential approaches to ferroelectric nonvolatile random access memory with nondestructive readability and ferro electric domain imaging microscopy using THz radiation as a sensitive probe are demonstrated.
Abstract: Terahertz (THz) radiation has been observed from multiferroic ${\mathrm{BiFeO}}_{3}$ thin films via ultrafast modulation of spontaneous polarization upon carrier excitation with illumination of femtosecond laser pulses. The radiated THz pulses from ${\mathrm{BiFeO}}_{3}$ thin films were clarified to directly reflect the spontaneous polarization state, giving rise to a memory effect in a unique style and enabling THz radiation even at zero-bias electric field. On the basis of our findings, we demonstrate potential approaches to ferroelectric nonvolatile random access memory with nondestructive readability and ferroelectric domain imaging microscopy using THz radiation as a sensitive probe.
212 citations
TL;DR: In this article, a thermally active superconductor-metal coupled resonator based hybrid terahertz metamaterial was demonstrated on a sapphire substrate that shows tunable transparency and slow light behavior.
Abstract: Structured plasmonic metamaterial devices offer the design flexibility to be size scaled for operation across the electromagnetic spectrum and are extremely attractive for generating electromagnetically induced transparency and slow-light behaviors via coupling of bright and dark subwavelength resonators. Here, we experimentally demonstrate a thermally active superconductor-metal coupled resonator based hybrid terahertz metamaterial on a sapphire substrate that shows tunable transparency and slow light behavior as the metamaterial chip is cooled below the high-temperature superconducting phase transition temperature. This hybrid metamaterial opens up the avenues for designing micro-sized active circuitry with switching, modulation, and “slowing down terahertz light” capabilities.
194 citations
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TL;DR: An overview of the status of the terahertz technology, its uses and its future prospects are presented in this article, with a focus on the use of the waveband in a wide range of applications.
Abstract: Research into terahertz technology is now receiving increasing attention around the world, and devices exploiting this waveband are set to become increasingly important in a very diverse range of applications. Here, an overview of the status of the technology, its uses and its future prospects are presented.
5,512 citations
TL;DR: Although not yet providing compelling mechanical strength or electrical or thermal conductivities for many applications, CNT yarns and sheets already have promising performance for applications including supercapacitors, actuators, and lightweight electromagnetic shields.
Abstract: Worldwide commercial interest in carbon nanotubes (CNTs) is reflected in a production capacity that presently exceeds several thousand tons per year. Currently, bulk CNT powders are incorporated in diverse commercial products ranging from rechargeable batteries, automotive parts, and sporting goods to boat hulls and water filters. Advances in CNT synthesis, purification, and chemical modification are enabling integration of CNTs in thin-film electronics and large-area coatings. Although not yet providing compelling mechanical strength or electrical or thermal conductivities for many applications, CNT yarns and sheets already have promising performance for applications including supercapacitors, actuators, and lightweight electromagnetic shields.
4,596 citations
TL;DR: In this paper, the authors summarize both the basic physics and unresolved aspects of BiFeO3 and device applications, which center on spintronics and memory devices that can be addressed both electrically and magnetically.
Abstract: BiFeO3 is perhaps the only material that is both magnetic and a strong ferroelectric at room temperature. As a result, it has had an impact on the field of multiferroics that is comparable to that of yttrium barium copper oxide (YBCO) on superconductors, with hundreds of publications devoted to it in the past few years. In this Review, we try to summarize both the basic physics and unresolved aspects of BiFeO3 (which are still being discovered with several new phase transitions reported in the past few months) and device applications, which center on spintronics and memory devices that can be addressed both electrically and magnetically.
3,526 citations
TL;DR: Graphene and its derivatives are being studied in nearly every field of science and engineering as mentioned in this paper, and recent progress has shown that the graphene-based materials can have a profound impact on electronic and optoelectronic devices, chemical sensors, nanocomposites and energy storage.
3,118 citations
TL;DR: An overview and evaluation of state-of-the-art photodetectors based on graphene, other two-dimensional materials, and hybrid systems based on the combination of differentTwo-dimensional crystals or of two- dimensional crystals and other (nano)materials, such as plasmonic nanoparticles, semiconductors, quantum dots, or their integration with (silicon) waveguides are provided.
Abstract: Graphene and other two-dimensional materials, such as transition metal dichalcogenides, have rapidly established themselves as intriguing building blocks for optoelectronic applications, with a strong focus on various photodetection platforms The versatility of these material systems enables their application in areas including ultrafast and ultrasensitive detection of light in the ultraviolet, visible, infrared and terahertz frequency ranges These detectors can be integrated with other photonic components based on the same material, as well as with silicon photonic and electronic technologies Here, we provide an overview and evaluation of state-of-the-art photodetectors based on graphene, other two-dimensional materials, and hybrid systems based on the combination of different two-dimensional crystals or of two-dimensional crystals and other (nano)materials, such as plasmonic nanoparticles, semiconductors, quantum dots, or their integration with (silicon) waveguides
3,025 citations